Articles: brain-injuries.
-
Journal of neurotrauma · Jun 2001
Age-Dependent vasopressinergic modulation of Noc/oFQ-induced impairment of NMDA cerebrovasodilation after brain injury.
This study was designed to characterize the role of vasopressin in nociceptin/orphanin FQ (NOC/oFQ)-induced impairment of NMDA cerebrovasodilation after fluid percussion brain injury (FPI) as a function of age in newborn (1-5 days old) and juvenile (3-4 weeks old) pigs equipped with a closed cranial window. Previous studies have observed that NOC/oFQ is released into CSF and contributes to impaired NMDA induced pial artery dilation following FPI to a greater extent in newborn versus juvenile pigs. Topical vasopressin (40 pg/mL), a concentration approximating that observed in CSF following FPI in the newborn, increased CSF NOC/oFQ from 69 +/- 3 to 102 +/- 8 pg/mol under non-FPI conditions. ⋯ The greater release of vasopressin following FPI in the newborn contributes to the corresponding greater release of NOC/oFQ in the newborn versus the juvenile. Moreover, vasopressin also contributes to the impairment of NMDA cerebrovasodilation after brain injury to a greater extent in newborn versus juveniles. These data suggest that vasopressin modulates NOC/oFQ-induced impairment of NMDA cerebrovasodilation after brain injury in an age-dependent manner.
-
Activation of microglial cells and astrocytes after CNS injury results in changes in their morphology, immunophenotype and proliferative activity and has neurotrophic as well as neurotoxic consequences. However, little is known about the exact time course of glial activation as regards their proliferative activity and their fate. In this study, quantification of the densities of proliferating and non-proliferating microglial cells and astrocytes was carried out over 30 days by counting differentially labeled cells in the striatum and substantia nigra pars reticulata (SNr) after injection of quinolinic acid into the rat striatum. ⋯ At later time points, a dense astrogliosis with proliferating astrocytes developed in the dorsal and medial striatum. At 30 days p.i., in the entire striatum a dense astrogliosis was detected. The SNr showed a short period of microglial activation and proliferation and a long lasting astrogliosis without proliferation
-
Traumatic brain injury (TBI) is characterized by a high mortality which is largely determined by the initial cerebral trauma, secondary brain injury or indirectly during a Multiple Organ Dysfunction Syndrome (MODS). Therefore, we analyzed IL-6, IL-8, and IL-10 in cerebrospinal fluid (CSF) and in plasma with respect to blood-brain barrier (BBB) integrity in 29 patients suffering from isolated TBI. IL-6 and IL-8 were significantly increased compared to baseline levels early after trauma in CSF and plasma. ⋯ BBB dysfunction was temporary present in 23 patients. Significant correlations between BBB dysfunction and cytokines were not found. Thus, alterations of the BBB seems not to influence the distribution pattern of interleukines in CSF and plasma after trauma.
-
Pial artery dilation in response to activators of the ATP-sensitive K(+) (K(ATP)) and calcium-sensitive K(+) (K(Ca)) channels is impaired after fluid percussion brain injury (FPI). Vasopressin, when coadministered with the K(ATP) and K(Ca) channel agonists cromakalim and NS1619 in a concentration approximating that observed in cerebrospinal fluid (CSF) after FPI, blunted K(ATP) and K(Ca) channel-mediated vasodilation. Vasopressin also contributes to impaired K(ATP) and K(Ca) channel vasodilation after FPI. In addition, protein kinase C (PKC) activation generates superoxide anion (O(2)(-)), which in turn contributes to K(ATP) channel impairment after FPI. We tested whether vasopressin generates O(2)(-) in a protein kinase C (PKC)-dependent manner, which could link vasopressin release to impaired K(ATP) and K(Ca) channel-induced pial artery dilation after FPI. ⋯ These data show that vasopressin, in concentrations present in CSF after FPI, increased O(2)(-) production in a PKC-dependent manner and contributes to such production after FPI. These data show that vasopressin contributes to K(ATP) but not K(Ca) channel function impairment in a PKC-dependent manner after FPI and suggest that vasopressin contributes to K(Ca) channel function impairment after FPI via a mechanism independent of PKC activation.